Fitbit & Kardia disagree …. - Atrial Fibrillati...

Atrial Fibrillation Support

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Fitbit & Kardia disagree ….

KazDD profile image
21 Replies

I am wondering if anyone else has experienced this, last night around 11.30pm I felt my heart misbehave for the first time since my ablation pre-covid. A run of very strong fast beats then fast & erratic. I tried relaxing for a while playing a game on my phone to occupy my mind, but the rate & rhythm continued to be erratic.

Interestingly my Fitbit reading is very different to my Kardia reading. My Kardia is showing “poss AF” with a heart rate jumping between 111 - 156. My Fitbit’s heart chart is fairly normal other than a couple of spikes up to 118. I have tried taking my pulse manually but am having trouble finding the pulse in my wrist! I took a PIP tablet Bisoprolol Fumarate at 1.30am but it doesn’t seem to have made any difference.

Anyone else had this with Fitbit/ Kardia readings?

Thank you in advance for any replies

Kaz

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KazDD
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21 Replies
pottypete1 profile image
pottypete1

Not had this problem but my gut feeling would be to trust the Kardia.

Pete

KazDD profile image
KazDD in reply to pottypete1

judging by the way I felt I would agree, thanks Pete.

KazDD profile image
KazDD in reply to KazDD

I’m back in normal rhythm now although blood pressure is a bit low

mjames1 profile image
mjames1

The algorithms used by Kardia and Fitbit are imperfect, however the EKG generated by Kardia tells the story. If you cannot read it yourself, have it read by an ep, or have it read by one of Kardia's cardiologists, if that service is available to you. That said, I find Kardia's determinations correct most of the time with afib, unless there are multiple ectopic beats which can throw it off.

Jim

Tigger_2 profile image
Tigger_2 in reply to mjames1

Not only do ectopics upset measurements, but they upset pacemakers too.I get 1000 PVCs per hour and these effectively slow the pacemaker down because it counts the PVCs as normal and doesn't bother firing a pulse and instead of a minimum of 70 BPM, I get 40 and feel awful.

I'm on 10 mg Bisoprolol to subdue the ectopics and seeing the consultant in 3 weeks time.

Buffafly profile image
Buffafly

Fitbit doesn’t work with AF as far as I know, because the technology can’t keep up. Similar to oximeter.

lovetogarden profile image
lovetogarden

My Fitbit doesn’t always reflect my tachycardia events accurately. It definitely takes longer to show the actual fast heart rate. Where the Kardia shows it quite instantly. If the event lasts long enough, the Fitbit catches up. With the fluctuating heart rates of afib, the Fitbit would have a harder time, even though some models are meant to alert you to afib. Kardia is definitely more accurate.

Omniscient1 profile image
Omniscient1

I don't trust Fitbit to get my HR correct (and there are many different types). I'd go with the Kardia.

kkatz profile image
kkatz

Sorry I really don't rate Fitbit even after years of using them.I only use a charge 4 and many a time when going on my walk or doing an excercise class it will show something like 145 when I know it is max 90/95.

macymoo007 profile image
macymoo007

When I was in hospital earlier this month with a constant 130 HR I kept my Apple Watch on. On a couple of occasions when my obs were being done, my watch was as accurate as the ecg machine but the blood pressure/oxygen level reader wasn’t always the same. The nurse said the ecg was more accurate. So I deduced from this that my Apple Watch is accurate. Is there nothing you can compare to

LadyZ13 profile image
LadyZ13

My Fitbit was all over the shop when I was in Atrial Flutter (we assume!) for 2 months. Some weird peaks (150bpm) that didn't seem to correlate with the pulse in my wrist (not that it was easy to tiw down, it felt erratic). I was told just to ignore it and during cardiac rehab was told not to use it as an indicator of exertion but go off how I was feeling instead. The Kardia has, I believe, more points of contact so is going to give you a more accurate reading and trace. That said, it's amazing what the Fitbit can do from your wrist - it was the first thing to flag possible Afib (which showed up as flutter on the subsequent holter) when I wasn't really feeling symptoms.

Ducky2003 profile image
Ducky2003

My Fitbit does have an AF alert, which thankfully hasn't triggered, but I wouldn't trust it entirely, even measuring steps. Repetitive movements of your arm if you're stood still measure steps and I've even had it chart a HR of over 100 when I wasn't even wearing the bloomin thing.I use it as a guide and it's great to alert me to messages of missed calls when I've got my phone muted when I'm seeing patients.

I could barely find my pulse manually when having an AF episode, which was the big indicator for me.

KazDD profile image
KazDD in reply to Ducky2003

'I could barely find my pulse manually when having an AF episode' - yes, that's what I find too.

'Repetitive movements of your arm if you're stood still measure steps' - apparently I did around 5000 steps whilst wall paper stripping

Ducky2003 profile image
Ducky2003 in reply to KazDD

🤣. My step count an HR measure shoot up when I'm filing patients feet.🤣

KazDD profile image
KazDD

OK so I won't be taking too much notice of my Fitbit going forward 😂😂

WOW .... I had forgotten how rough it can make you feel after a 9-10 hour run of Afib! I still feel exhausted and my chest & back are quite achy 😞

Dodie117 profile image
Dodie117

my reading suggests Fitbit only works when you are at complete rest/no moving

ie asleep. Mine has triggered a few times when I was asleep and gives very detailed report. However when I am awake and have an AF episode (confirmed by Kardia) it does not alert me.

This from US fda:

April 12, 2022

Today, the U.S. Food and Drug Administration is providing an at-a-glance summary of news from around the agency:

* On April 8, the FDA cleared Fitbit’s Irregular Rhythm Notifications software intended to be used with certain wrist-worn consumer products to analyze pulse rate data and identify episodes of irregular heart rhythms that may suggest possible atrial fibrillation. Fitbit’s Irregular Rhythm Notifications software is designed to notify the user when an irregular heart rhythm occurs while the user is not moving. It is intended for over-the-counter use. It is not intended to diagnose or treat atrial fibrillation; for use in people under 22 years of age; or for use in individuals previously diagnosed with atrial fibrillation.

KazDD profile image
KazDD

interesting, I have not set up my Fitbit for detecting Afib as I already have a diagnosis but was a bit surprised by the difference in the heart rate reading when in Afib, but I was fast too

frazeej profile image
frazeej

I was not satisfied at all with the ecg I was getting from my FitBit Sense, so got a Kardia. MUCH better!!!!! Half the time my Fitbit won't even register my breathing rate at night (no, I'm not dead!), so I question the accuracy of any other data it provides. Another example: Resting HR. Provides a graph for the whole day.........except it will show bursts of resting HR 146+ for an hour at a time. NO WAY that's accurate!

Bikedennis profile image
Bikedennis

Many times lately mt Fitbit reads much higher than my radial pulse. Sometimes the Fitbit is twice the radial.

Chinkoflight profile image
Chinkoflight

My GP recommended a Kardia and said of my printouts they were clearer and more informative than the surgery ECG printouts.

Gertsen profile image
Gertsen

I turned off the heart but on my Fitbit as it was incorrect both with Kardia and manually checking my pulse

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